Sodium lauryl sulfate (SLS) is a very commonly used foaming agent in oral care products, in particular, toothpaste. SLS offers certain properties over other surfactants that make it desirable for the use in oral applications. These properties include high foaming properties, low oral toxicity, and low cost. However, SLS has several disadvantages that can greatly limit its use in oral care applications. These disadvantages include foam suppression by divalent cations such as Ca2+, and the tendency to denature proteins. Protein denaturation is a particular problem that can lead to skin irritation and incompatibility with proteinacious materials. This means that SLS may not be favorably combined with proteinacious additives, which may be desirable, including enzymes and beneficial bacteria.
There have been several attempts to address these problems, including use of alkyl polyglucosides. Alkyl polyglucosides (APGs) are high foaming surfactants employed in a number of personal care applications, including oral care. APGs are very mild to proteinacious surfaces and are known to improve the foaming properties of SLS in the presence of hard water cations. However, APGs have a bitter aftertaste which can limit their use in oral care application.
Therefore, there exists a need to develop surface active materials that can mitigate the effect of SLS on protein without negatively impacting foam. In particular, for oral care applications, there also exists a need for surfactants which solve the above problems but also do not negatively impact taste.